Thanks for the info everybody, I'm going to look for that spare pin & I'll rifle my shed for the tools in the list.
I'm not so sure about drilling the akas. It looks a really good job, and I'm sure it does the trick but, I would prefer not to drill the akas if I can do it another way. I'm going to give it some thought.
Thanks again all.
Ger

I've found the pencil anodes I've used can break fairly easily at the thread (the anode is quite porous for galvanic corrosion efficiency), so I would recommend going with a zinc strip anode, which I am sure can be found on the Web. Then, install it with aluminum rivets.

I'm sure I've committed some overkill with the zinc anodes. Probably one zinc anode attached to each Xbar would solve the problem. Drilling into the aluminum is going to give you the clean metal surface needed to make contact through the rivet to the anode--there must be electrical conductance. The electrical conductance of these materials is the cause of the galvanic corrosion throughout the akas and Xbars, and the conductance makes the zinc anode work.

So drilling into the akas is not inherently a problem. What you put in those holes can be--and Hobie needs to solve their galvanic corrosion problem involving akas and Xbars. I think it would be simple enough to REMOVE ALL STEEL/ALUMINUM CONTACTS THEREBY ELIMINATING THE GALVANIC CELL. Get rid of stainless steel screws in the akas and Xbars. Replace the stainless steel aka/Xbar pin with an aluminum alloy pin suitable to withstand the stress. Isolate the mast holder from the Xbar with suitable insulation.

Everyone in the marine fabrication knows that aluminum/steel contact is deadly to aluminum. Get rid of of the source of the problem.

In the mean time, as Philip suggests we will help one another through this wonderful forum which Hobie generously provides.

Keith

_________________2015 AI 2, 2014 Tandem

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein

Rather than paint, I'm surprised these parts are not hard coat anodized. In my experience, paint just doesn't get it for protecting aluminum. Powder coated or otherwise is just a false sense of security. I've had several powder coated aluminum items that the salt breached the coating and spread under the paint...turning the aluminum to oxide powder. You need to use a conversion coating to really get any protection at all.

Maybe use this paint over it with another UV top coat. http://www.por15.com/prodinfo.asp?grp=1&dept=1 it has a good resistance to salt. Using both of the above is probably the next best thing to hard coat anodizing, though still far from being equal. And oh, please dispose of this stuff properly after use...

Actually it's probably bettter than powder coating. I say this because if you take a piece of aluminum to a powder coater, they will sandblast it clean...even if you have already done so and applied alodine 1201. They will tell you they won't guarantee the job, unless 'they' blast it.

If you search around your local area you may find someone that does industrial coatings. Hopefully, with tanks large enough to do hard coat anodizing. They will sandblast and prep the parts prior to running them through the process. Even with a anodized hard coating, one little pin prick will allow salt in to under mine it. There is no perfect solution.

_________________TC

Last edited by Rockets on Sun Jan 11, 2009 7:30 pm, edited 1 time in total.

Excellent points, especially regarding the alodine coating before painting. If I am forced to take care of this problem myself, I will get the parts sand blasted, then coat it with alodine, and finally put a good coat of marine paint on it.

From my reading, I understand that anodizing aluminum does not protect it from galvanic corrosion. Hobie needs to remove the source of the problem: Aluminum/steel contact.

Keith

_________________2015 AI 2, 2014 Tandem

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein

No, it won't. At work we pre-paint any surfaces where dis-similar metals come in contact with a special zinc chromate paint, that I don't think the general public can purchase...or probably couldn't afford it if they could. The stuff is pretty nasty, w/ MEK and a number of other solvents in it.

I have to tell you though that POR-15 paint is some TOUGH STUFF. It's impervious to just about everything, and it ain't cheap either! If you put two things together with it while wet, you will never get them apart when it dries.

Water and humidity cause it to harden, so you need really dry conditions when you apply it. I've made the mistake of using it outside on high humidity days...not good. Take your work inside the A/C for the few hours it needs to set up if you have to. Yeah it's inconvient, but if you want something to last...

Most paints, including probably most marine paints "breathe" and let moisture penetrate. Hell, even fiberglass absorbs water...anyway POR-15 supposedly does not, which is what makes it a better product. I'm not saying it's fool proof, because there is no such thing... imho.

A couple of years ago I had the opportunity to go to this place http://www.sypristechnologies.com/Sypri ... x?Page=281They do among other things industrial/ mil spec testing of anything you can imagine. While I was there for my own project, they just happened to be salt spray testing the POR-15 primer. Having been a user of it prior, I asked them how it held up, and was told "Excellent".

All in all, hard coating would be my first choice and is the way to go. It's really not that expensive for what you're getting...just a little more than powder coating. The trick is finding a place that does it, or has a tank large enough to accomodate your item. You probably have someone near you, look in the yellow pages and give them a call for an estimate...you might be surprised.

I haven't got the problem yet but thought I would try this product when I did:
http://www.hammeriteproducts.com.auThe finish is fabulous and can be painted by brush directly over rusty metal.

Quote:

WHERE CAN IT BE USED?Steel, iron, aluminium and galvanised surfaces. Hammerite can be applied directly onto new metal, bare rusted iron and steel and painted surfaces. For aluminium, galvanised or zinc sprayed surfaces, first apply a coat of quality, water based deep etch metal primer. Hammerite can be used on wood (if external use a primer) fibreglass, and certain plastics not affected by hot solvents - to provide a fabulous decorative hammer tone finish.

Where uncertain, patch test with Hammerite for 72 hours to first check compatability.

Thanks, I'm no expert on this mind you, but living on the coast I've learned what works and what doesn't around the house. Well... that and my job has taught me a few things. I usually can't contribute much on the forum, in contrast to what I gain, so when I can, I try to offer the best of what I know. Sometimes, I just show my ignorance

Without looking at the MSDS or Technical Data sheet it's hard to say if the Hammerite is a kissing cousin or not with POR 15. They do share the same thinner though. The POR 15 is an Isocyanate based paint (IF I remember correctly). You know the stuff Super glue, Gorilla glue etc. are based on. You definetly want to give it some respect as I'm sure it's a hazard to ones health.

Given that you don't have the problem yet...this might be a good time to do a pre-emptive strike. Seal the existing paint before you do have problems. Just a thought to chew on. I'd request a data sheet from both manufacturers, salt spray test results and compare.

As I said previous, hard coat anodize would be my first choice for repair/restoration, if possible. Most larger towns or cities will have at least one vendor that can do it. I know there are vendor on the net that you could ship to and have it done also.

Another good thing about hard coating is, the inside of the tube gets treated too...not as easy to do w/ paint. Yeah, you can dunk the part in an 1201 alodine bath as a pre-treatment, but unless you were able to strip the interior paint, it's not going to be effective. Anodizing on the other hand is a multi-step process, where the part is dunked in a series of temperature controlled tanks. The first being rather caustic.

Alodine with a good non-permeable primer and top coat would be my second choice. It's probably not going to last as long as an anodized part and in a few years will more likely need to be retreated.

Ger,--and Hobie needs to solve their galvanic corrosion problem involving akas and Xbars. I think it would be simple enough to REMOVE ALL STEEL/ALUMINUM CONTACTS THEREBY ELIMINATING THE GALVANIC CELL. Get rid of stainless steel screws in the akas and Xbars. Replace the stainless steel aka/Xbar pin with an aluminum alloy pin suitable to withstand the stress. Isolate the mast holder from the Xbar with suitable insulation.

Everyone in the marine fabrication knows that aluminum/steel contact is deadly to aluminum. Get rid of of the source of the problem.

In the mean time, as Philip suggests we will help one another through this wonderful forum which Hobie generously provides.

Keith

This may not be the ideal thread to post this reply but I will post here and consider starting a new thread in due course.

I took my akas around to my highly respected "metal man" today (an expert german craftsman). He admired the quality of the aluminium welding and thought the paint job was floorless. We discussed various options as to how it might be improved (powder coating, anodized) but the one that struck me as the most durable was to make the akas etc in stainless steel. He suggests 32mm x 316 grade stainless steel in the lightest grade available - given that s/s is about four times stronger than aluminium.
He touched up one of my akas that I had managed to damage the paint on with his Hammer Tone (Hammerite) paint - which should help to prevent the serious corrosion problem identified by several veterans.

Chekika (Keith) I would suggest you consider cleaning off any loose rust/paint, use a suitable aluminium metal primer to etch any bare metal surface, and repaint your akas etc with this product - which is available worldwide. It can be applied with a brush and looks excellent.

I would be very interested in hearing Hobie's response to the stainless steel option. I appreciate that it will more than double the weight, but to counteract that, the reduced diameter and thinnest possible grade (given that s/s is approx 4x stronger than aluminium) should go some way towards counteracting that issue. Matt Miller, could you give us a response on this please??

Regarding the paddles and other corrosion issues that I am experiencing, it may be due in part to how I use my boat. I pretty much only use it on multiday trips, and I can't rinse anything off in fresh water until I get home--usually 4-7 days. That is certainly going to accelerate this problem. Of course, people who do not rinse their equipment well--including inside the hull and inside the paddle--are also going to experience corrosion problems.

Keith

_________________2015 AI 2, 2014 Tandem

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein

Stainless? I think that could be cost prohibitive. If the coating is done properly... aluminum is the ticket. We have done aluminum spars and crossbars for over 30 years. Sometimes there can be production issues, but normally... they are quite good.

Stainless? I think that could be cost prohibitive. If the coating is done properly... aluminum is the ticket. We have done aluminum spars and crossbars for over 30 years. Sometimes there can be production issues, but normally... they are quite good.

Matt - Thank you for your response.
I discussed this briefly with my metal man and he thought that if they are massed produced, the cost would be negligible. I appreciate that it is one thing to express an opinion and another to actually do a cost analysis. I guess that's the point though - the only way to find out would be to do a cost comparison. I have some other kits that turn a pushbike into a "boat"
http://www.sbk-oz.com/index.php?option= ... 5&Itemid=6They are of Italian origin and all parts are very high quality stainless steel (for strength and durability) along with some plastic and aluminium parts.
I haven't had my AI long enough to experience any corrosion issues but having seen some of the photos on the forum, I thought this might be a real solution. If the weight and cost were marginally more, I would expect the consumer would happily pay it to have a much more durable and attractive craft. As an alternative. maybe you could sell them as an alternative option at time of purchase. Mickey

Back to paddles. I was at a Hobie dealer today (not "my" dealer) and saw that Hobie is shipping a plastic/fiberglass paddle with many of their other kayaks. Maybe they will do the same for the AI before long. Seems Hobie is moving in the right direction. Excellent.

Keith

_________________2015 AI 2, 2014 Tandem

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein